My sister has just returned from the hospital 3 weeks agao. She is extremely weak and has been diagnosed with low potassium. She is 77 years old... She is a totally different person since returning home. Can hardly walk and now is being given liquid potassium. Is there anythng else that could be her problem....She said that it has been coming on for some time...She would be just fine, and then all at once fees so very exhausted and extremely weak that she felt like she could not walk...I am writing because I am 69 and also have had the same feeling for over a year now....We both have limited our salt intake over the years, can you tell us anything that might help?